Electrosurgical instruments and connections thereto

ABSTRACT

An electrosurgical instrument includes jaws having an electrode configuration utilized to electrically modify tissue in contact with one or more electrodes. The instrument is removably connectable to an electrosurgical unit via an electrosurgical connector extending from the instrument and a receptacle on the electrosurgical unit. The electrosurgical instrument is rotatable without disrupting electrical connection to the electrodes of the jaws. One or more of the electrodes is retractable. The electrosurgical unit and instrument optimally seals and/or cuts tissue based on identifying the tissue and monitoring the modification of the tissue by the application of radio frequency energy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/936,914, filed Mar. 27, 2018, which is a continuation of U.S.application Ser. No. 15/136,652, filed Apr. 22, 2016, which is acontinuation of U.S. application Ser. No. 13/366,487, filed Feb. 6,2012, now U.S. Pat. No. 9,320,563, which is a continuation ofInternational Application No. PCT/US2011/054661, filed on Oct. 3, 2011,which claims the benefit of US Provisional Application No. 61/389,012,filed on Oct. 1, 2010, the entire disclosures of which are incorporatedby reference as if set forth in full herein.

BACKGROUND

The present application relates generally to electrosurgical systems andmethods and more particularly to electrosurgical instruments andconnections between the instruments and electrosurgical units.

Surgical procedures often involve cutting and connecting bodily tissueincluding organic materials, musculature, connective tissue and vascularconduits. For centuries, sharpened blades and sutures have beenmainstays of cutting and reconnecting procedures. As bodily tissue,especially relatively highly vascularized tissue is cut during asurgical procedure, it tends to bleed. Thus, medical practitioners suchas surgeons have long sought surgical instruments and methods that slowor reduce bleeding during surgical procedures.

More recently, electrosurgical instruments have become available thatuse electrical energy to perform certain surgical tasks. Typically,electrosurgical instruments are hand instruments such as graspers,scissors, tweezers, blades, needles, and other hand instruments thatinclude one or more electrodes that are configured to be supplied withelectrical energy from an electrosurgical unit including a power supply.The electrical energy can be used to coagulate, fuse, or cut tissue towhich it is applied. Advantageously, unlike typical mechanical bladeprocedures, application of electrical energy to tissue tends to stopbleeding of the tissue.

Electrosurgical instruments typically fall within two classifications:monopolar and bipolar. In monopolar instruments, electrical energy of acertain polarity is supplied to one or more electrodes on theinstrument. A separate return electrode is electrically coupled to apatient. Monopolar electrosurgical instruments can be useful in certainprocedures, but can include a risk of certain types of patient injuriessuch as electrical burns often at least partially attributable tofunctioning of the return electrode. In bipolar electrosurgicalinstruments, one or more electrodes is electrically coupled to a sourceof electrical energy of a first polarity and one or more otherelectrodes is electrically coupled to a source of electrical energy of asecond polarity opposite the first polarity. Thus, bipolarelectrosurgical instruments, which operate without separate returnelectrodes, can deliver electrical signals to a focused tissue area witha reduced risk of patient injuries.

Even with the relatively focused surgical effects of bipolarelectrosurgical instruments, however, surgical outcomes are often highlydependent on surgeon skill. For example, thermal tissue damage andnecrosis can occur in instances where electrical energy is delivered fora relatively long duration or where a relatively high-powered electricalsignal is delivered even for a short duration. The rate at which atissue will achieve the desired coagulation or cutting effect upon theapplication of electrical energy varies based on the tissue type and canalso vary based on pressure applied to the tissue by an electrosurgicalinstrument. However, even for a highly experienced surgeon, it can bedifficult for a surgeon to assess how quickly a mass of combined tissuetypes grasped in an electrosurgical instrument will be fused a desirableamount.

Attempts have been made to reduce the risk of tissue damage duringelectrosurgical procedures. For example, previous electrosurgicalsystems have included generators that monitor an ohmic resistance ortissue temperature during the electrosurgical procedure, and terminatedelectrical energy once a predetermined point was reached. However, thesesystems have had shortcomings in that they have not provided consistentresults at determining tissue coagulation, fusion, or cutting endpointsfor varied tissue types or combined tissue masses. These systems canalso fail to provide consistent electrosurgical results among use ofdifferent instruments having different instrument and electrodegeometries. Typically, even where the change is a relatively minorupgrade to instrument geometry during a product's lifespan, theelectrosurgical unit must be recalibrated for each instrument type to beused, a costly, time consuming procedure which can undesirably remove anelectrosurgical unit from service.

SUMMARY

Generally, electrosurgical instrument, units and connections betweenthem are provided. Various embodiments described with variousinstruments, units and/or connections can be interchangeable orapplicable as provided below. In one embodiment, an electrosurgicalinstrument is provided and comprises a first jaw and a second jawopposing the first jaw and is coupled to the first jaw to capture tissuebetween the first and second jaws. A first electrode is connected to thefirst jaw and extendable from a first position within the first jaw to asecond position outside the first jaw. The first electrode iselectrically connected to a stationary electrode positioned on the firstor the second jaw.

In another embodiment, an electrosurgical unit comprising a radiofrequency (RF) amplifier is provided. The RF amplifier is configured tosupply RF energy to coagulate and cut tissue and the RF amplifiersupplies RF energy to tissue that is not sufficient to completelycoagulate tissue prior to the supplying of RF energy to cut tissue.

In another embodiment, an electrosurgical instrument is provided andcomprises a first jaw and a second jaw opposing the first jaws andcoupled to the first jaw to capture tissue between the first and secondjaws. First, second, third and fourth electrodes are disposed on thefirst jaw and a fifth electrode is disposed on the second jaw.

In yet another embodiment, an electrosurgical instrument is provided andcomprises a first jaw and a second jaw opposing the first jaws andcoupled to the first jaw to capture tissue between the first and secondjaws. A first electrode is connected to the first jaw and a movablecutter is connected to the first or second jaw. The instrument alsocomprises an actuator having a stationary handle and a movable triggerconnected to at least one of the first and second jaws to move the jawsbetween spaced and proximate positions, an elongate shaft connected tothe actuator and the first or second jaws, and a blade trigger connectedto a blade shaft connected to the movable cutter disposed within theelongate shaft and movable along a longitudinal axis. The instrumentalso comprises a first stop limiting distal travel of the blade shaftalong the longitudinal axis.

In one embodiment, an electrosurgical instrument comprises a first jawand a second jaw opposing the first jaws and coupled to the first jaw tocapture tissue between the first and second jaws. A first electrode isconnected to the first jaw and an actuator comprises a rotatableelongate shaft connected to the actuator and the first or second jaws;at least one conductive connection surrounds a portion of the rotatableelongate shaft within the actuator; and at least one stationary contactis disposed within the actuator and electrically connectable to the atleast one conductive connection, the at least one conductive ringelectrically connected to the first electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

The present inventions may be understood by reference to the followingdescription, taken in connection with the accompanying drawings in whichthe reference numerals designate like parts throughout the figuresthereof.

FIG. 1 is a perspective view of an embodiment of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 2A is a side view of an electrosurgical instrument with anassociated coupler to connect to an electrosurgical unit in accordancewith various embodiments of the invention.

FIG. 2B is a dissembled view of an electrosurgical instrument with anassociated coupler to connect to an electrosurgical unit in accordancewith various embodiments of the invention.

FIG. 3A-1 is a side view of an interior of an actuator of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 3A-2 is a side view of an interior of an actuator of anelectrosurgical instrument in accordance with various embodiments of theinvention with some components removed to facilitate viewing.

FIG. 3A-3 is a perspective view of conductive connectors of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 3A-4 is a perspective view of an interior of an actuator of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 3A-5 is a perspective view of a conductive ring of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 3A-6 is a perspective view of an interior of an actuator of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 3A-7 is a perspective view of a contact brush of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 3A-8 is a perspective view of a rotary connector with an exemplarysingle wire in accordance with various embodiments of the invention.

FIGS. 3B-1 to 3B-2 illustrate side views of an interior of an actuatorof an electrosurgical instrument at different stages of actuation inaccordance with various embodiments of the invention.

FIG. 4A illustrates a perspective view of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 4B illustrates a perspective view of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 4C illustrates a cross-sectional view of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 5 is a focused view of one of the jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 6 is a side view of jaws of an electrosurgical instrument inaccordance with various embodiments of the invention.

FIG. 7 is a perspective view of jaws of an electrosurgical instrument inaccordance with various embodiments of the invention.

FIG. 8 is a focused view of one of the jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 9 is a front view of jaws of an electrosurgical instrument inaccordance with various embodiments of the invention.

FIG. 10 is a perspective view of jaws of an electrosurgical instrumentin accordance with various embodiments of the invention.

FIG. 11 is a perspective view of an electrosurgical instrument with anassociated coupler to connect to an electrosurgical unit in accordancewith various embodiments of the invention.

FIG. 12 is a side view of an electrosurgical instrument with portions ofan associated coupler to connect to an electrosurgical unit inaccordance with various embodiments of the invention.

FIG. 13A is a side view of an interior of an actuator of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIGS. 13B-1 to 13B-3 illustrate side views of an interior of an actuatorof an electrosurgical instrument at different stages of actuation inaccordance with various embodiments of the invention.

FIG. 13C-1 illustrates a perspective view of jaws and a shaft of anelectrosurgical instrument in accordance with various embodiments of theinvention with a portion of the shaft removed (not shown).

FIG. 13C-2 illustrates a cross-sectional view of a cover tube of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 13C-3 illustrates a perspective view of a cover tube of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 13C-4 illustrates a side view of a cover tube of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 13C-5 illustrates a perspective view of jaws and a shaft of anelectrosurgical instrument in accordance with various embodiments of theinvention with a portion of the shaft removed (not shown).

FIG. 13C-6 illustrates a perspective view of jaws and a blade shaft ofan electrosurgical instrument in accordance with various embodiments ofthe invention.

FIG. 13C-7 illustrates a side view of a blade shaft of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 13C-8 illustrates a cross-sectional view of a shaft of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 14 is a disassembled view of an electrosurgical instrument andcoupler in accordance with various embodiments of the invention.

FIG. 15A illustrates a top view of jaws of an electrosurgical instrumentin accordance with various embodiments of the invention.

FIG. 15B illustrates a bottom view of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 15C illustrates a bottom view of one of the jaws of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 15D illustrates a top view of an opposing jaw of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 15E illustrates a perspective view of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 15F illustrates a side view of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 15G illustrates a cross-sectional view of jaws of anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 16 is a side view of jaws of an electrosurgical instrument inaccordance with various embodiments of the invention.

FIG. 17 is a perspective view of jaws of an electrosurgical instrumentin accordance with various embodiments of the invention.

FIG. 18 is a perspective view of jaws of an electrosurgical instrumentin accordance with various embodiments of the invention.

FIG. 19 is a disassembled view of an electrosurgical instrument andcoupler in accordance with various embodiments of the invention.

FIG. 20 is a side view of a coupler of an electrosurgical instrument toconnect to an electrosurgical unit in accordance with variousembodiments of the invention.

FIG. 21 is a disassembled view of a coupler of an electrosurgicalinstrument to connect to an electrosurgical unit in accordance withvarious embodiments of the invention.

FIG. 22 is a disassembled view of a coupler of an electrosurgicalinstrument to connect to an electrosurgical unit in accordance withvarious embodiments of the invention.

FIG. 23 is a perspective view of a connector in accordance with variousembodiments of the invention.

FIG. 24 is a perspective view of connector in accordance with variousembodiments of the invention.

FIG. 25 is a back view of connector in accordance with variousembodiments of the invention.

FIG. 26 is a back view of circuitry, memory and pin arrangements of aconnector in accordance with various embodiments of the invention.

FIG. 27 is a perspective view of circuitry, memory and pin arrangementsof a connector in accordance with various embodiments of the invention.

FIG. 28 is a perspective view of circuitry, memory and pin arrangementsof a connector in accordance with various embodiments of the invention.

FIG. 29 is a front view of a receptacle of an electrosurgical unit inaccordance with various embodiments of the invention.

FIGS. 30A-B are perspective views of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIG. 31 is a perspective view of jaws of an electrosurgical instrumentin accordance with various embodiments of the invention.

FIG. 32 is a perspective view of jaws of an electrosurgical instrumentin accordance with various embodiments of the invention.

FIG. 33 is a perspective view of jaws of an electrosurgical instrumentin accordance with various embodiments of the invention.

FIGS. 34A-B are perspective views of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIGS. 35A-B are perspective views of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIGS. 36A-D are perspective views of jaws of an electrosurgicalinstrument in accordance with various embodiments of the invention.

FIGS. 37A-B are perspective views of an electrosurgical instrument inaccordance with various embodiments of the invention.

FIG. 38 is an exemplary chart illustrating electrode configurations inaccordance with various embodiments of the invention.

FIG. 39A-1 is a perspective view of a monopolar pad and anelectrosurgical unit in accordance with various embodiments of theinvention.

FIG. 39A-2 is a close-up perspective view of a monopolar port of anelectrosurgical unit in accordance with various embodiments of theinvention.

FIG. 39B is a perspective view of a monopolar pad, a monopolar and/orbipolar electrosurgical instrument, and an electrosurgical unit inaccordance with various embodiments of the invention.

FIG. 40 is a flow chart illustrating a pre-cut process for anelectrosurgical instrument in accordance with various embodiments of theinvention.

FIG. 41 is a block diagram of an electrosurgical unit in accordance withvarious embodiments of the invention.

FIG. 42 is semi-schematic diagram of an electrosurgical unit inaccordance with various embodiments of the invention.

DETAILED DESCRIPTION

The electrosurgical system in one embodiment includes an electrosurgicalunit or generator capable of supplying radio frequency energy to one ormore removably coupled electrosurgical instruments or tools. Examples ofsuch instruments and connectors between the instrument and theelectrosurgical unit are provided in the drawings. Each instrument isparticularly designed to accomplish particular clinical and/or technicaloperations or procedures. Additionally, the coupling or partnershipbetween the electrosurgical unit and instruments are specificallyprovided to further enhance the operational capabilities of both theelectrosurgical unit and instruments such that clinical and/or technicaloperations are achieved.

One such electrosurgical instrument is shown in FIGS. 1-10 whichillustrate a fusion and cutting electrosurgical instrument 10connectable to an electrosurgical unit in accordance with variousembodiments of the invention. As illustrated, the instrument includesjaws 12 for manipulating tissue and the actuator 14 for manipulating thejaws. A shaft 16 connects the jaws to the actuator. In one embodiment,the shaft and jaws are sized and arranged to fit through a cannula toperform a laparoscopic procedure. In one embodiment, the actuatorincludes a barrel connected to a pivotable trigger 112 for opening andclosing of the jaws and to capture and/or compress tissue between thejaws and a rotatable knob 114 and connector providing rotationalmovement of the jaws. The actuator may also include switches 116, 118 toactivate cut, coagulate, seal, fuse or other electrosurgical activitiesand indicators to identify or highlight the activated or deactivatedactivity.

The jaws 12 include a first jaw 102 and a second jaw 104. The first jawis stationary and the second jaw is movable through actuation by theactuator coupled to the second jaw via the shaft and/or componentstherein. In one embodiment, both jaws may be movable or mobility of thejaws reversed, e.g., the movable jaw is stationary and the stationaryjaw is movable. It should also be noted that the first or second jawbeing upper or lower jaws is relative as the shaft and the jaws arerotatable and thereby can assume either position. The first jaw includesfour electrodes. The first and second electrodes 103 a, 103 b aresubstantially hemispherical in shape and cover or occupy a majority ofthe total surface area of the first jaw. In one embodiment, thehemispherical shape of the electrodes and/or a corresponding matingshape of the second jaw promote tissue after being cut to slide away orotherwise disengage from the jaw. The first and second electrodes arealso mirror image of each other and thereby occupy equal halves or sideportions along the first jaw 102 as the electrodes extend substantiallyalong the length of the second jaw 104. Disposed between the first andsecond electrodes are third and fourth electrodes 105 a, 105 b generallyrectangular in shape extending substantially perpendicular relative tothe first and second electrodes 103 a, 103 b and also extending alongthe length of the first jaw. The edges or the upper portions of thethird and fourth electrodes can be beveled or otherwise tapered,slanted, rounded or curved to provide an atraumatic edge to assist in asurgical procedure, e.g., grasping tissue, or alternatively a definededge to assist for example in cutting tissue.

The third electrode 105 a extends towards the second jaw and the fourthelectrode 105 b extends away from the second jaw. The third electrode105 a extends or has a height somewhat greater than the height orextension of the fourth electrode 105 b extending out of the first jaw.The fourth electrode also includes a distal portion 105 b′ that extendsalong the tip of the first jaw 102 curving up along the tip. Thelengthwise path of the third and fourth electrodes substantially followsthe lengthwise shape of the first jaw. Thus, in the illustratedembodiment, the third and fourth electrodes are somewhat curvilinear.

When the first and second jaws 102, 104 are closed, e.g., in a proximaterelationship with each other, the third electrode 105 a is substantiallycovered by the second jaw 104 and thereby leaving the third electrodeunexposed. The fourth electrode 105 b however remains uncoveredregardless of the position of the second jaw. Each of the electrodes onthe first jaw are electrically insulated or isolated from each other.Additionally, operationally, each electrode can assume a particularelectrical polarity. As such, each electrode can assist in accomplishinga particular surgical functionality, e.g., cut, coagulation, fuse, seal,weld, etc. In one embodiment, the second jaw can also include one ormore electrodes, e.g., a fifth or sixth electrode, which in conjunctionwith the electrodes on the first jaw can also assist in accomplishingthe desired surgical functionality.

In one embodiment, when the first and second jaws 102, 104 are closed(or not fully opened or partially closed) and a user activates acoagulation operation or condition, the first and second electrodes 103a, 103 b assume a particular polarity and a fifth electrode 107 assumesan opposite polarity, through which RF energy is transmitted throughclamped tissue between the first and second jaws to coagulate thetissue. Likewise, when the user activates a cut operation and the firstand second jaws are closed, the first and second electrodes 103 a, 103 bassume a particular polarity and the third electrode 105 a on the firstjaw assumes an opposite polarity to first coagulate the tissue and thento cut tissue between the first and second jaws 102, 104 and inparticular at a point or section where the third electrode 105 acontacts the tissue between the jaws. In one particular embodiment, in acut operation with the first and second jaws are closed, the first andsecond electrodes 103 a, 103 b assume opposite polarity to coagulate thetissue up to and/or prior to complete coagulation or a predeterminedpre-cut condition. After reaching the pre-cut condition based on apredetermined phase value, in one embodiment, the first and secondelectrodes 103 a, 103 b assume a polarity opposite to the polarity ofthe third electrode 105 a. In one embodiment, the actuator 14 includes atrigger switch that is inactive or not activated by the position of thetrigger positioned away from the switch.

Additionally, when the first and second jaws are not closed (fullyopened or partially opened) and a user activates a coagulation operationor condition, the first electrode 103 a assumes a particular polarityand the second electrode 103 b assumes an opposite polarity, throughwhich RF energy is transmitted through tissue between the first andsecond electrodes 103 a, 103 b to coagulate the tissue. Likewise, whenthe user activates a cut operation and the first and second jaws are notclosed, the first and second electrodes assume a particular polarity andthe third and fourth electrode 105 a, 105 b on the first jaw 102 assumesan opposite polarity to first coagulate the tissue and then to cuttissue between the electrodes and in particular at a point or sectionwhere the third electrode contacts the tissue between the jaws. Itshould be appreciated that over or completely coagulating tissueincreases the difficulty in cutting the tissue as the tissue'sconductivity is substantially reduced. This is contrary to the tendencyto “over coagulate” tissue to ensure that blood loss is avoided (i.e.,the tissue is sealed).

In one embodiment, a trigger switch 103 of the actuator 14 is activatedby the position of the trigger 112 causing contact with the switch. Thetrigger in the illustrated embodiment includes a flexible arm 101connected to or incorporated with the trigger utilized to activate ordeactivate a trigger switch in the actuator 14. The trigger switch 103is internal or housed within the actuator and not accessible by asurgeon. The trigger switch however activates or permits the activationor effect of one or more external switches that is accessible by thesurgeon. For example, a “cut” button or switch accessible by a surgeonwill not operate or cause the application of RF energy to cut tissueeven if the button is depressed by the surgeon unless the internaltrigger switch is also activated. In one embodiment, the internaltrigger switch is only activated depending on the position of thetrigger and/or the jaws. The internal trigger switch can also beactivated via relays based on commands or programming provided by theelectrosurgical unit, the instrument and/or the connector. It should beappreciated that in various embodiments the internal trigger switch doesnot activate or permit by itself the activation of RF energy and therebyavoids unintended operation of the instrument without active anddeliberate participation by the surgeon. Additionally, it should beappreciated that in various embodiments the switches accessible by thesurgeon can only activate while the internal trigger switch is alsosimultaneously active or activated and thereby avoids unintendedoperation of the instrument without active and deliberate participationby the surgeon and active communication or deliberate programming orcommands embedded or provided for the electrosurgical unit, theinstrument and/or the connector.

It should thus be appreciated that tissue between the first and secondjaws can be cut with the jaws closed or not closed. Additionally, tissuecan be cut beneath and/or in front of the first jaw, i.e., tissue notbetween the first and second jaws, when the first and second jaws arenot closed (the cutting occurring to the tissue between the fourth andfirst electrodes; the fourth and second electrodes; and/or the fourthand first and second electrodes). It should also be appreciated that theelectrodes to assume the appropriate polarity or connection for aparticular operation, e.g., cut or coagulation, are switched in orconnected to the energizing circuitry of the electrosurgical unit toapply the specific RF energy to cut or coagulate tissue. Such switchingor control information in one embodiment is provided via script datastored on a memory chip of a plug adapter or coupler connectable to theelectrosurgical instrument.

As previously described, in one embodiment, the first jaw 102 isstationary or not movable and includes inner and outer verticalelectrodes. Such an electrode configuration provides directed energydelivery based on the position of one jaw relative to the other jaw. Forexample, the electrode configuration provides cutting at the tip of ajaw and/or along the length of both the outer and inner surfaces of thejaw. Also, with the electrode configuration being located on a jaw thatis stationary relative to the other jaw operation when the jaws are opencan be performed such that a surgeon can manipulate the direction orpath of the cut directly through manipulation of the actuator as the jawis stationary in relation to the shaft and the actuator. In oneembodiment, tissue captured between the jaws can also be cut by theelectrodes on both jaws operating together.

It should be appreciated that the addition of multiple electrodes on oneor more jaws is not a trivial design choice. Reducing the numberelectrodes is often desired, especially in the limited confines oflaparoscopic procedures, to avoid shorting or undesired thermal spreador modification of tissue, e.g., charring or cutting of tissue,introduced at least by the additional conductive material proximate theactive or energized electrodes. Accordingly, the electrodes as providedin various embodiments are specifically arranged, structured andutilized to overcome such challenges.

In one embodiment, an electrosurgical instrument is provided thatincludes multiple cutting blades or surfaces. Some or all the blades aremovable and/or electrically connected. Operationally, the instrument orparts thereof can be energized to fuse or coagulate and cut tissue asneeded. In another embodiment, one or more blades are stationary and/orelectrically connected.

In one embodiment, wires are welded onto the electrodes in the first jaw102. The wires are routed around a rotary connector 27 and conductiverings 24 a -24 d are attached to the rotary connector within theactuator 14. In one embodiment, a rotary lock is installed and holds theconductive rings in place. In one embodiment, conductive ring 24 a iscoupled to the electrode 103 a and conductive ring 24 d is coupled tothe electrode 103 b. The conductive ring 24 b is coupled to theelectrode 105 a and conductive ring 24c is coupled to the electrode 105b. The rotary connector 27 includes one or more slots through whichwires from electrodes are threaded or managed through slots. Conductiverings are secured to the rotary connector such that individualcorresponding wires for associated electrodes are electrically connectedto associated conductive rings. As such, the conductive rings rotate asthe rotary connector rotates along with the associated wires extendingfrom the electrodes of the jaws through the shaft and to the rotaryconnector and thus the wires do not wind around the shaft as the jawsare rotated.

The actuator 14 also includes contact brushes 26 a-d are disposed incontact with an associated conductive ring 24 a-d. For example, in theillustrated embodiment, contact brush 26 a is positioned next conductivering 24 a. Each contact brush is also connected to a wire or similarconnections to the connector and ultimately to an electrosurgical unitto provide or communicate RF energy, measurement, diagnostic or similarsignals through an associated electrode at the jaws of theelectrosurgical instrument. Slots within the handle of the actuator inone embodiment facilitate the wire placement and connection with acontact brush and the electrosurgical unit. As such, the conductiverings provide a conduction or communication surface that is continuallyin contact with the contact brushes and vice versa regardless of therotation of the shaft. In one embodiment, the contact brushes areslanted or biased to maintain contact with the conductive rings.

A “U” shaped tube clip 25 within the actuator 14 is welded onto a wirein which the other end of the wire is welded to the second jaw 104. Inone embodiment, the second jaw 104 is held in place by a pull tube. Thepull tube serves as an electrical connection for the second jaw 104. Theconductive rings and clip provides constant electrical conductivitybetween the electrodes and the electrosurgical unit while simultaneouslyallowing or not hindering complete 360 degrees of rotation in anydirection of the jaws 102, 104. For example, wires coupled to theelectrodes to the rings or clip follow the rotational movement of thejaws and the shaft attached thereto and as a result do not getintertwined or tangled within or along the shaft or the actuator therebylimiting rotational movement, disconnecting or dislodging theconnections and/or interfering with operation of the actuator.

In one embodiment, individual wires are welded to individual electrodesof the jaws of the electrosurgical instrument. The wires, e.g., wire 29,are threaded along the shaft connected to the jaws through a rotary knoband into slots in a rotary connector 27. In one embodiment, some of thewires are placed on one side of the connector and other wires on anopposing side of the connector. The wires are staggered along the lengthof the connector to match the staggered placement of the conductiverings. In one embodiment, the staggered placement prevents inadvertentshorting or conduction between rings. Conductive rings are thus in oneembodiment slide over the connector and are placed in spaced slots alongthe connector to mate each conductive ring to an associated staggeredwire. Individual wires in one embodiment are also installed into slotsin the handle of the actuator and an associated contact brush isinstalled over the associated wire to mate each wire to an associatedcontact brush. The rotary connector thus installed into the handle ofthe actuator mates or sets up an electrical connection or conductionarea for each conductive ring with a corresponding contact brush.

Turning now to FIGS. 11-19, a fusion and cutting electrosurgicalinstrument 20 is shown connectable to an electrosurgical unit inaccordance with various embodiments of the invention. The instrument 20includes jaws 22 connected to a shaft 26 that is connected to anactuator 24 which when manipulated manipulates the jaws 22. In oneembodiment, the actuator includes a floating pivot mechanism 221including a pivot block connected to a trigger 222 for the opening andclosing of the jaws and to capture and/or compress tissue between thejaws. The actuator in one embodiment also has a rotary knob 224 andconnector providing rotational movement of the jaws and in oneembodiment also includes a blade trigger 225 coupled to a push bar orblade shaft coupled to or incorporating a distal cutting element totranslate the cutting element through the jaws and to cut tissue betweenthe jaws. The actuator may also include switches 226, 227, 228 toactivate cut, coagulate, seal, fuse or other similar electrosurgicalactivities and indicators to identify or highlight the activated ordeactivated activity.

In accordance with various embodiments, a blade or cutter 191 isincluded in the instrument and is movable relative to the jaws 22 of theinstrument. The cutter is displaced substantially orthogonal to surfaceone or both jaws and is movable along a longitudinal axis of theinstrument. In one embodiment, the cutter is positioned horizontally orparallel relative to one or both jaws. The cutter in one embodiment canmove outside the confines of the jaws or is placed on the outside orouter surface of one or both jaws. For example, the cutter can act as aretractable electrode or retractable blade placed within one or bothjaws and exposed externally or on the outside of a jaw upon manipulationby an actuator coupled to the cutter. The cutter edge can extend alongall or some of the cutter and some or all of the edge is sharpened,beveled, energized or otherwise configured to cut tissue.

In the illustrated embodiment, the cutter 191 traverses through achannel within the jaws to cut tissue between the jaws. The channel doesnot extend beyond the outer periphery of the jaws and thus the cutterremains within the distal confines of the jaws. A blade shaft 196 isconnected or incorporated with the cutter as a monolithic structureextends into the actuator. A blade trigger upon actuation moves thecutter through the channel in the jaws. The blade shaft 196 is biased topull the cutter back to its initial rest position once the trigger isreleased. In one embodiment, a spring coupled to the blade shaft biasesthe cutter towards the actuator. Actuation of the blade trigger thusovercomes the spring bias to move the cutter distally through, out oralong the inside or outside of one or both jaws.

In one embodiment, one or more stops 195, 197 along the blade shaftlimits movement of the blade shaft 196 and thus the cutter 191. In theillustrated embodiment, a stop projection disposed on or within theblade shaft moves with the blade shaft and when moved distally to apredetermined point, e.g., near a distal end of the channel in a jaw,the stop projection interacts with a corresponding stop projection orslot 194 preventing further distal movement of the stop projectionbeyond the stop slot. In one embodiment, the stop slot is disposed on,from or within a cover tube 192 disposed over the blade shaft andpositioned to contact the stop projection on the blade shaft when thecutter is moved distally to a predetermined point.

In one embodiment, a second stop projection 197 is disposed on or withinthe blade shaft 196 and spaced from a first stop projection 195. Thesecond stop projection is placed closer to the actuator or away from thejaws 22. In the illustrated embodiment, the second stop projection 197prevents the spring from pulling the blade proximally beyond apredetermined point, e.g., near a proximal end of the channel in a jaw.As such, in various embodiments, the blade stop limits forward and/orreverse travel of the blade or cutter when extended or retraced eithertowards or away from the distal end of the instrument. The blade stopsin one embodiment are crimped or deformed portions 194 in the cover tube192. The crimped portions interacting with the stop projections of theblade shaft act as a positive stop as the inside dimension of the covertube is narrower than the overall width of the stop projections on theblade shaft. A pull tube 193 coupled to the jaws to actuate and/orenergize one or both jaws is disposed over the blade shaft and in oneembodiment includes one or more slots to provide exposure or interactionof the stops of the blade shaft with the stops of the cover tube.

The stops ensure that if force is applied the cutter will not beyond apredetermined point. The cutter could be allowed to continue to movedistally or proximally upon actuation and the distal or proximal end ofthe channel or portions thereof can halt further movement of the cutter.However, if further pressure or bias is applied to move the cutterdistally or proximally, the contact with one or both jaws under pressurecan damage or dull the cutter. The stop projections prevent such acondition. In one embodiment, the second stop projection preventsfurther movement of the cutter proximally and thus the spring biasingthe cutter towards the proximal direction, the spring can hold thecutter in place. Thus, the cutter can be moved along tissue to cuttissue with the jaws opened or closed without movement of the bladeshaft through movement of the instrument along or through tissue. Tissuepressed against the cutter is cut as the pressure or force of the springalong with the interaction of the stop projections holds the cutter inplace.

In one embodiment, the jaws 22 include a stationary first jaw 202 and amovable second jaw 204 that moves relative to the first jaw. In oneembodiment, both jaws may be movable or the first jaw movable and thesecond jaw stationary. The first jaw 202 is entirely conductive orincludes conductive material. In one embodiment, the first jaw includesan electrode generally planar and covering or extending over an uppersurface of the first jaw. The second jaw 204 includes first and secondelectrodes 205, 206 with an insulator between the electrodes. In oneembodiment, the second electrode 206 is on an upper portion of thesecond jaw 204 distal from the first jaw 202 and the first electrode 205is on a lower portion of the second jaw 204 proximate to the first jaw202. The second jaw is pivotally connected to the first jaw or the shaftor other components connected to the first jaw. Through this pivotconnection, the first jaw 202 in one embodiment is electricallyconnected to the second electrode 206 of the second jaw 204. The secondelectrode 206 is entirely conductive or includes conductive material andis generally shaped like the first jaw. The second electrode 206 in oneembodiment is generally hemispherical. The first jaw 202 in oneembodiment is generally hemispherical. Tissue however clamped orcaptured between the first and second jaws 202, 204 is positionedbetween the first electrode and the second jaw. As such, the secondelectrode 206 in one embodiment does not participate or is not involvedelectrically in the cutting or sealing of tissue grasped or capturedbetween the first and second jaws 202, 204. The second electrode 206when electrically added or switched in, in one embodiment, is involvedin the cutting and/or sealing of tissue outside or at least with tissuein contact with the second electrode. In one embodiment, thisconfiguration makes it unnecessary to electrically insulate the firstjaw and second jaw and in one embodiment may be commonly connected via ajaw pin. As such, manufacturing is eased and multiple or excessiveelectrical connections are reduced.

For example, in one embodiment, the first electrode 205 of the secondjaw 204 and the first jaw 202 are electrically connected to assume afirst and second polarity such that tissue positioned between (clampedor not clamped) and in contact with the first electrode 205 and thefirst jaw 202 can be sealed when a user activates a sealing operation.As such, RF energy appropriate for sealing tissue is transmitted throughthe tissue between the first electrode 205 and first jaw 202 to seal thetissue. In one embodiment, a movable cutting blade can be activated bythe user to cut the tissue between the first electrode 205 and first jaw202. The cutting blade in one embodiment is electrically conductive andenergized such that RF energy appropriate for cutting tissue istransmitted between the cutting blade and the first jaw 202, second jaw204, or both. In one embodiment, the cutting blade is stationary. Thecutting blade in one embodiment may be relatively blunt or sharp thatmay or may not depend on the electrical connectivity of the blade. Theremay also be multiple blades and some or all may be electricallyconductive or connected. The cutting blade in one embodiment ispositioned generally perpendicular to the first jaw 202 and/or cantraverse through the length or a portion thereof of the first or secondjaws.

In one embodiment, tissue outside of the first and second jaws 202, 204can be cut and/or coagulated. In one embodiment, the second electrode206 and first jaw 202 can be energized to coagulate tissue between thecontact point or area of the second electrode to tissue and the contactpoint or area with the first jaw. As such, jaws are positioned on itsside in its opened or closed position and can be dragged or slid acrossthe tissue to coagulate and/or cut tissue. Also, the jaws can bepositioned with its front or tips of the jaws (opened or closed)contacting tissue and dragged or slid across the tissue to coagulateand/or cut tissue. In one embodiment, the first electrode 205 of thesecond jaw 204 and the second electrode 206 of the second jaw 204 areelectrically connected to assume a first and second polarity such thattissue positioned between or in contact with the first and secondelectrodes to be cut and coagulate when a user activates a respectivecut or coagulate operation.

As such, RF energy appropriate for cutting or coagulating tissue istransmitted through the tissue between the first electrode 205 andsecond electrode 206 to respectively cut, coagulate, fuse or weld thetissue. As such, second jaw 204 can be dragged, pushed or slid acrosstissue to coagulate and/or cut tissue. In one embodiment, cutting orcoagulation is only allowed when jaws 202, 204 are partially or fullyspaced from each other. In one embodiment, a switch or sensor isactivated to indicate the spaced relationship or the lack thereofbetween the jaws to allow activation of cut or coagulation of thetissue.

In one embodiment, the first electrode 205 extends along an outerportion of the distal end or tip of the second jaw 204. The first andsecond electrodes 205, 206 can be energized to cut, coagulate, fuse orweld tissue between or in contact with the electrodes. By limiting thefirst electrode to a specific area or arrangement relative to the secondelectrode, the focus or applicable energizing area can be limited to thespecified portion of the first electrode and the second electrode 205,206. In one embodiment, the second electrode 206 can also be similarlyarranged to extend along a limited portion of the second jaw 204. In theillustrated embodiment, an insulator 207 disposed adjacent the firstelectrode 205 limits the focus area of the first electrode. In oneembodiment, the size, shape and/or orientation of the first electrode,the second electrode and/or an additional provided electrode is limitedto provide the appropriate or desired focus area. The first electrodeextending along the outer periphery of the second jaw is positionedgenerally horizontal relative to the second jaw and in one embodimentmay be relatively blunt. The orientation, size and location of the firstelectrode can vary based on the desired surgical operation and there maybe additional electrodes similarly positioned.

The first electrode 205, the first jaw 202 and/or the second electrode206 in one embodiment is a contiguous or monolithic electrode with acontiguous or monolithic seal surface. In one embodiment, the monolithicseal surface includes spaced or interrupted portions to provide aplurality of seal paths or surfaces. For example, first electrode 205includes first and second seal paths 217 a, 217 b. The first and secondseal paths surround and are adjacent to the blade or cut channel of thejaw through which the blade or cut electrode is situated or traversestherethrough. In the illustrated embodiment, the monolithic seal surfacealso includes spaces or cavities 215 a, 215 b and a third and a fourthseal path 219 a, 219 b positioned near but spaced from the first andsecond seal paths. The first and second seal paths in one embodiment areinner paths relative to the outer paths of the third and fourth sealpaths. The multiple interrupted or spaced seal paths provide redundantseal areas or portions of the tissue being sealed separated by a portionof the tissue not electrically or otherwise treated or manipulated bythe jaws. As such, by situating a separated or unaffected tissue betweenseal paths, the overall tissue seal is enhanced and thermal spread alongthe tissue and effects thereof are reduced. In the illustratedembodiment, tissue between the first seal path and the fourth seal pathremains unaffected by energy being transmitted to the electrode whiletissue along the first and third seal paths is electrically sealed.Likewise, tissue between the second seal path and the fourth seal pathis electrically sealed and the tissue between the paths or within oralong the cavities remains unaffected. Tissue along the cavities is alsonot compressed or mechanically manipulated as compared to the tissuealong the seal paths.

In one embodiment, the first electrode 205 can be activated by the userto cut, coagulate, fuse or weld tissue in contact with or between thefirst electrode 205 and the first jaw 202 and/or the second electrode206. In one embodiment, the second electrode 206 and the first jaw 202share a common electrical contact and/or common polarity such that RFenergy can be transmitted between the first electrode 205 and the firstjaw 202 and/or between the first electrode 205, the second electrode 206and the first jaw 202.

In one embodiment, when the jaws are not fully opened or closed, i.e.,in a state or condition between being open and being closed, tissuepositioned between the jaws 202, 204 can be fused. Automatic disruptionof RF energy in one embodiment however is not used, is not activated oris deactivated as the appropriate conditions for automatic disruption ofRF energy is not satisfied or cannot be assured. Cutting can also beprevented (mechanically and/or electrically). Identification of theintermediate state in one embodiment is determined based on theactivation or lack thereof of a switch and/or sensor within theinstrument adjacent the trigger and/or jaws or detecting the position ofthe trigger or the jaws relative to each other.

In accordance with various embodiments, electrosurgical RF energy to cutand/or coagulate tissue in a bipolar fashion utilizes both an active anda return electrode and can be used for example in general andgynecological laparoscopic procedures. In such configurations, thedesired surgical effect (e.g., cut, coagulate, etc.) is based upon thecurrent density ratio between the electrodes, the electrode geometry andthe current and voltage supplied to the electrodes. In one embodiment,cutting tissue utilizes a voltage output greater than 200 V andcoagulating utilizes a voltage below 200V. Current density is measuredas the (Delivered Current)/(Electrode Surface Area). As such, the activeand return electrodes can be assessed by the following current densityratio: Active Electrode/Return Electrode=(Large Current Density)/(SmallCurrent Density). It should be appreciated that an electrode can assumeor switch between roles as an active electrode or a return electroderelative to another electrode based on current density, electrodegeometry and/or current and voltage supplied to the electrodes.Generally, the active and the return electrodes are electricallyinsulated or isolated from each other.

Various electrode configurations of the jaws of the electrosurgicalinstrument in accordance with various embodiment of the invention areshown in FIGS. 30-38. In various embodiments, at least one or only oneelectrode is located on one of the jaws. For example, the electrode inone embodiment is located on the top jaw and horizontally orientedrelative to the jaw. It should be appreciated that the electrode couldbe on an opposite jaw than illustrated and the top and bottom jaws arerelative to each other. As such, referral to a top jaw can equally be areferral to a bottom jaw as well as movable jaw to stationary jaw.

In FIGS. 30A-B, a movable jaw 602 includes an outer vertical electrode605. This electrode configuration provides cutting at the tip of anarticulating or movable jaw and/or along the length of the jaw. In oneembodiment, the cutting follows in an articulating manner and/or pathrelative to the shaft and actuator of the instrument. For example,tissue can be cut as the top jaw opens as the electrode on the jaw isparallel or in-line with the path that the jaw travels (e.g., path 601and/or 603 (in both or one direction)). In the illustrated embodiment,the electrode 605 in conjunction with a larger conductive portion 606surrounding the electrode on the jaw or a second electrode 607 conductRF energy there between to effectuate the cutting path.

In one embodiment, a stationary jaw 704 includes an outer verticalelectrode 705 as shown in FIG. 31. This electrode configuration providescutting at the tip of a stationary jaw 704 and/or along the length ofthe outer portion of the jaw. The electrode 705 in one embodimentoperates in conjunction with either an inner or an outer electrodeacting as another electrode to conduct RF energy there between. In oneembodiment, a movable jaw 702 does not include an electrode or isotherwise insulated or isolated from the electrode 705. In operation, asurgeon can manipulate the direction or path of the cut directly throughthe manipulation of the actuator as the jaw remains stationary relativeto the shaft of the instrument.

Referring now to FIG. 32, in one embodiment, one of the jaws 802includes a horizontal electrode 803 and a vertical electrode 805. Thiselectrode configuration provides directed energy delivery based on theposition of the jaws relative to each other. The configuration alsomakes it unnecessary to electrically insulate the top jaw actuatingmember from the lower jaw. While the jaws are closed, the horizontalelectrode 807 on the lower jaw 804 can be used to dissect tissueutilizing the lower jaw 804 as a return electrode. While the jaws areopen, the vertical electrode 805 can cut tissue at the tip of the topjaw 802 as well as along the length of the top jaw in an articulatingmanner relative to the shaft and hand-piece of the instrument. Tissuecan be cut as the top jaw opens because the active electrode is parallelto the path that the top jaw travels. The active electrode utilizes thetop jaw actuating member as the return electrode. The orientation ofboth electrodes can be switched, e.g., vertical to horizontal andhorizontal to vertical, to achieve similar effects.

In one embodiment, an electrosurgical cutting electrode 811 can be usedto dissect tissue as shown in FIG. 33. A mechanical cutting blade 812 isused to divide tissue captured in the jaws 815, 816 of the instrumentalong the length of the jaws of the instrument by activation of a leverlocated on the actuator of the instrument. It should be appreciated thatthe mechanical blade and electrical electrodes can be reversed. In oneembodiment, a first cutting electrode 811 can be used to dissect tissue.A second cutting electrode 812 is used to divide tissue captured in thejaws of the device by using the lower jaw 816 as a return electrode.This second electrode can travel along the length of the jaws of theinstrument by activation of a lever located on the actuator of theinstrument.

In various embodiments, electrodes (and portions in which they areattached) can be used to probe and/or manipulate tissue in a physicalmanner when not electrically active. In various embodiments, retractableelectrodes provide an atraumatic jaw assembly for tissue contact and formovement through trocar seals. In one embodiment, retraction of acutting electrode into the body of either jaws of the instrument canfacilitate the removing or cleaning eschar that has built up on theelectrode.

In one embodiment, the retraction of an electrode 91 can be actuatedthrough movement in relation to the trigger of the actuator (FIGS.34A-B). For example, the retraction would occur in relation to themovement of the jaws. Such an actuation can indicate which position theelectrode can be used to cut tissue. In one embodiment, when theelectrode is extended, the electrode can be activated and when retractedinactive. The placement of the retractable electrode can be on either orboth jaws. In one embodiment, the retraction of the electrode 91 canoccur through a lever or similar actuator separate from the trigger oractuator (FIGS. 35A-B). As such, the electrode can be extended andretracted independently of the jaw position. The electrode can also beactivated independently and in an extended position.

The retractable electrodes described above and as shown in FIGS. 36A-Dcan be rounded 95, pointed 96, L-Hook shaped 93, or J-Hook shaped 94. Invarious embodiments in which the electrodes are L-Hook shaped, J-Hookshaped or similarly shaped and retractable, such electrodes can be usedto capture tissue between the jaws of the instrument and/or the hookportion of the electrode.

In one embodiment, an electrode on one of the jaws may be separated orbe two adjacent electrodes (e.g., a distal electrode and a proximalelectrode). Each electrode can be energized simultaneously orindividually. Also, one of the electrodes can allow a different tissuetype to be treated differently from the other electrode (e.g., one cutsand the other coagulates, one treats one type of tissue and the other isused for another type of tissue). The separate electrodes can alsoprovide a comparison of tissue type or phase monitoring to ensure propertreatment (e.g., cut, coagulation, etc.) of the tissue or multipletissue types in contact with the separate electrodes. The other jaw orother portions of the same jaw in one embodiment can act as an electrodein which RF energy is exchanged between the electrodes and the jaws.

Referring now to FIGS. 20-29, electrosurgical instruments areconnectable to an electrosurgical unit through a coupler 50 inaccordance with various embodiments of the invention. The coupler 50includes a plug 502 attached to a cable 501 attached to and extendingfrom the connecting instrument. Attached to the plug 502 is a connector503 which is connectable to the electrosurgical unit. In one embodiment,the plug 502 is not connectable to the electrosurgical unit without theconnector 503.

In one embodiment, the plug 502 is removably attached to a connector 503that is directly connectable to an electrosurgical unit. The connector503 provides a conduit such that radio frequency energy is supplied fromthe electrosurgical unit through the cable to the instrument.Additionally, communication back to the electrosurgical unit istransmitted through the cable and connector from the instrument. Forexample, the instrument via switches or actuation of the handle ortrigger transmits signals or closes circuits to ensure RF energy isdelivered as requested by the instrument.

The connector 503 in one embodiment includes memory circuitry 503 b′ anda pin arrangement 503 b″. The pin arrangement 503 b″ is specificallyarranged to couple to a corresponding pin arrangement 501d of the cable501 associated with the electrosurgical instrument. On the other end ofthe cable, contacts 501 a, 501 b, and 501 c are arranged to connect tocorresponding contact points for switches, indicators and/or sensors asappropriate for the associated electrosurgical instrument. Accordingly,the pin arrangements can vary to couple the cable to the connector 503and the contacts 501 a, 501 b, 501 c, 501 e, and 501 f can vary tocouple the cable to the corresponding electrosurgical instrument.

The memory circuitry in one embodiment includes instrument or tool datathat outlines the operation of the instrument in conjunction with theelectrosurgical unit. The tool data in one embodiment is transmittedfrom the chip to the electrosurgical unit. The unit in analysis of thetool data recognizes or identifies the electrosurgical instrument towhich the connector is attached thereto. Additionally, the tool dataincludes script information that describes the operational aspects ofthe attached electrosurgical instrument. For example, the scriptinformation can include a total number of electrodes on theelectrosurgical instrument and the state or condition in which one ormore of the electrodes are utilized or software to be transferred to anelectrosurgical unit upon successful electrical connection of theinstrument to the electrosurgical unit. The tool data can also includedata regarding various electrosurgical procedures to be performed by theinstrument and corresponding energy level ranges and durations for theseprocedures, data regarding electrode configuration of an instrument,and/or data regarding switching between electrodes to perform differentthe electrosurgical procedures. Similarly, customized data, e.g.,settings preferred by a particular surgeon or a surgical procedure to beperformed, can also be included in the tool data and utilized forexample to set the electrosurgical unit in a mode or particularconfiguration preferred by the surgeon, e.g., a particular power settingor the user interface's appearance or control.

In one embodiment, the electrosurgical unit has limited capabilities tosupply or not supply RF energy. The electrosurgical unit can alsoincrementally increase or decrease the amount or intensity of the supplyof RF energy. However, the control or regulation of the RF energy is notincluded or incorporated with the electrosurgical unit but instead islocated on the memory circuitry as script information. The scriptinformation provides the control data that directs the supply ofradiofrequency energy such that when a button or switch is activated bythe user, RF energy is directed to corresponding electrodes as indicatedin the control data. Similarly, the control data also includesinformation to identify and recognize the button being activated. Afterinitial handshaking between the electrosurgical instrument and the unitwhen an instrument is connected to the unit, the script information istransferred to the electrosurgical unit. In one embodiment, subsequentor further access or requests to deliver the script information to theunit is not provided or permitted to prevent reuse of the connector 503.

The connector in one embodiment is non-sterile and the cable and theelectrosurgical instrument to which the cable is connected are sterile.It should be noted that the non-sterile characteristic of the connectoris not typically used in the other electrosurgical systems. However, dueto the electrical components, e.g., the memory circuitry, within theconnector typical sterilization of the connector is not readilyavailable or usable. Accordingly, embedding or otherwise including suchcomponents with an electrosurgical instrument that must be sterile istypically not provided. However, by providing a separate and attachableconnector the electrosurgical systems can be customized and/orconfigured while the sterilization concerns are overcome.

In one embodiment, the connector 503 allows the electrosurgical unit tobe customizable and/or configurable to adjust or accommodate variouselectrosurgical instruments that are connectable to the electrosurgicalunit. Accordingly, as an electrosurgical instrument changes or improvesover time and/or surgical procedures or operational procedures change,the electrosurgical unit can be supplied the latest or most recentinformation from the connector specifically tailored or addressed to theelectrosurgical instrument attached thereto. Therefore, changes toinstrument or tool profiles and periodic tool updates can be rapidlymade without downtime to electrosurgical units, as the software forinstrument operation can reside with the electrosurgical instrumentitself, rather than the electrosurgical unit. Accordingly, updates canbe made during instrument production and thereby avoiding thepotentially expensive and time prohibited activity of removing orreplacing the electrosurgical unit from for example hospital operatingrooms to perform updates to the unit.

The connector 503 also ensures a proper connection between anelectrosurgical instrument and the electrosurgical unit. In oneembodiment, script information stored in the connector is tailored onlyfor the accompanying electrosurgical instrument and no other instrument.For example, if user connects a vessel sealer to the provided connector,the script information stored in the memory circuitry only includesinformation for that particular vessel sealer. Thus, if a user doesconnect the same connector to a different instrument, such as anelectrosurgical scalpel, (mechanical and electrical features aside thatprevent such attachment), the script information to recognize and/orsupply power to such an instrument is not available to theelectrosurgical unit. As such, even if a user activates the scalpel, theelectrosurgical unit without any script information about such aninstrument will not supply RF energy to the instrument. In this example,the script information provided is for a vessel sealer. Utilizing thisscript information the electrosurgical unit is also able to identifythat the attached device is not a vessel sealer and in particular notthe appropriate instrument for the provided script information. This inone embodiment can also be recognized by initial handshaking of anattached instrument and the electrosurgical unit, the script informationthereby also providing a layer of insurance for proper instrument usage.

The connector 503 in one embodiment also provides a uniformconfiguration for the connection to the electrosurgical unit on one sideor end and the plug of the electrosurgical instrument on the other end.The pin or recess arrangement 503 a, 503 b″' provides an uniform andexpected mating or coupling to corresponding pin or recess arrangementson the instrument ports of the electrosurgical unit. Similarly, the plug501d includes a recess or pin arrangement that couples to thecorresponding pin or recess arrangement 503 b″ of the connector 503.Covers 502 a, 502 b and 503 c cover or enclose the associated componentsof the plug 502 or connector 503. Accordingly, the connector 503provides a uniform mechanical connection between the electrosurgicalunit and the associated electrosurgical instrument. Therefore,manufacturing and operational use are facilitated. However, thecircuitry provided with the connector 503 can provide a customized ornon-uniform electrical connection between the unit and the instrumentand/or script information to the unit for the instrument. Therefore,upgrade flexibility and instrument customization are enhanced.

It should be appreciated that there are various RF electrosurgical unitsthat supply RF energy and likewise various electrosurgical instrumentsor tools that can connect to such electrosurgical units to receive thesupplied RF energy which is operationally used in various surgicalprocedures. However, particular electrosurgical instruments require oroptimally function when supplied RF energy within a particularspecification or manner. In some cases, such instruments orelectrosurgical units simply do not operate with the electrosurgicalunits or instruments, thereby leaving a surgical team to wonder if theinstrument or electrosurgical unit is defective. As a result, operatingdevices are improperly discarded or surgical procedures delayed as thesource of the problem is investigated and uncovered.

In other cases, the instruments or electrosurgical units do operatetogether in the sense that the instrument is supplied RF energy by theelectrosurgical unit. However, the instrument or electrosurgical unitexpecting a particular or specific application of such energy can resultin damage to the devices or improper operation of the instrument, e.g.,the instrument not cutting a tissue sufficiently or a vessel not sealingafter the application of RF energy by the instrument. Therefore, in somecases, particular electrosurgical instruments should not be connected toparticular RF electrosurgical units and vice versa.

Additionally, in particular cases, a specific operational quality andperformance of an electrosurgical instrument or electrosurgical unit isexpected by a surgical team for use in a particular surgical procedure.Such operational performance however results only when the specificelectrosurgical instrument is utilized with the specific electrosurgicalunit. Accordingly, this pairing of specialized devices is required toprovide the expected operational quality and performance. Therefore,there is a need to ensure the proper connection between electrosurgicalinstruments and electrosurgical units to ensure operational quality andperformance and to prevent unexpected and unintended operation failuresor damage to the devices.

In one embodiment, systems and methods are provided to ensure the properconnection of specialized or specific electrosurgical instruments to thespecialized or corresponding specific receptacles of an electrosurgicalunit. Improper connection or connection with a non-specializedelectrosurgical instrument with the specialized receptacles is thusprevented. As such, among other things, this ensures that onlyelectrosurgical instruments of a specific quality and performance areused that match the specific quality and performance of theelectrosurgical unit.

In one embodiment, the tool connector 503 mates with a tool connectorreceptacle 302 of a tool port of an electrosurgical unit. An embossmenton the connector and an excavation or channel 303 on the tool receptacleensures proper orientation upon instrument or tool insertion. Theembossment on the connector and the excavation on the receptacle alsoensures that proper or expected instruments are being plugged in thecorresponding instrument port, e.g., DC port versus a dedicatedinstrument port (and vice versa). Upon insertion, a latching mechanism,in one embodiment, including latch arms on the instrument plug andcorresponding latch shelves 301 on the receptacle locks the connection,resulting in an engagement of flat surfaced contact pads on theconnector with a series of extending pins 304, e.g., spring-loadedpogo-pins, of the receptacle of the electrosurgical unit. In oneembodiment, a series of pins extending from a receptacle of theelectrosurgical unit are removably and electrically coupled to flatsurface pads on the connector. As such, the flat surface pads do notinclude any mechanical connectors to interact or interlock the pins withthe associated pad. Additionally, in one embodiment, the connector orplug does not include mechanical connections or interlocks to couple thepins from the receptacle to the connector. In the illustratedembodiment, the contact pads are recessed within individual cavities inthe plug and the cavities do not interlock with the associated pinsextending to contact the associated contact pad when the plug isinserted into the receptacle. In one embodiment, the receptacle alsoincludes a switch 305 recessed within receptacle that is operativelyactivated by the plug and in particular an interlock pin or projection504 extending from the plug and being inserted into the receptacle. Inone embodiment, the receptacle is circular or similarly shaped alongwith the corresponding plug that reduces the overall surface or workingarea along the electrosurgical unit. In one embodiment, the pins extendfrom the plug or connector while flat surface pads are arrayed along thereceptacle of the electrosurgical unit.

In various embodiments, on the other side of the tool connector plugcontact pads are shown. In this view, a printed circuit board (PCB) witha circuitry housing an encrypted tool memory chip and a tool connectorhead that provides connection to the instrument are given. The toolconnector head in various embodiments connects the instrument electrodes(up to five), functional instrument switches (cut, coag and fuse),instrument position switches (instrument fully open and instrument fullyclose), as well as a three-colored LEDs in the electrosurgicalinstrument to the electrosurgical unit. As such, the pin/receptacleassignment on the instrument receptacles corresponds to thepin/receptacle assignment on the tool connector plug.

In one embodiment, script-based or instrument-specific generatorintelligence is stored in a non-volatile memory section of the memorychip in the tool connector that communicates with an electrosurgicalunit. A script parser in a central processing unit (CPU) of theelectrosurgical unit reads and processes tool script information suchas, but not limited to, instrument authentication (ensuring originalmanufacturer use), single-use assurance, instrument expiration date,instrument recognition, user interface control (electrosurgical unit'sdisplay and/or tones), instrument interface settings (e.g., LEDs oninstruments), electrode selection and electrosurgical unit settings(voltage and current) which can also be based on position of the jawelements (fully open or fully clamped), time-out limits to de-activatepower based on time, as well as tissue feedback-activated endpoints(e.g., fuse end point based on phase between voltage and current) andswitch points (e.g., switching from coag to cut, fuse to cut, based forexample on phase between voltage and current).

The memory chip in one embodiment is written by the electrosurgical unitCPU to store procedure-specific data such as, but not limited to, theserial number of the electrosurgical unit used, a time stamp ofinstrument connection, the number of instrument uses, the power settingused during each use, the tissue feedback data before, during and aftera instrument use, the nature of the instrument use (cut, coag, fuse),the duration of the instrument use, the nature of the shut off point(auto stop, fault, manual stop, etc.), as well as the event and natureof any faults (instrument short, expired or unrecognized instrument,etc.).

An embodiment of a pin-assignment for the dedicated RF instrumentreceptacles provides pin contacts numbered 1 through 8 are reserved forto the tool memory circuitry, pins 9 through 17 for the instrumentswitches and LEDs (cut, coag, fuse, instrument open, instrument close,red, blue, green LED and return), and pins 18 through 22 for fiveinstrument electrodes. In another embodiment a pin-assignment for thededicated DC instrument receptacle provides pin contacts numbered 1through 8 are reserved for to the memory circuitry, pins 9 through 17for the instrument switches and LED (onl, on2, on3, instrument position1, instrument position 2, red, blue, green LED and return), and pins 20and 21 for provision of DC power.

Electrosurgical systems and processes in various embodiments applymonopolar or bipolar high-frequency electrical energy to a patientduring surgery. Such systems and processes are particularly adapted forlaparoscopic and endoscopic surgeries, where spatially limited accessand visibility call for simple handling, and are used to fuse bloodvessels and weld other biological tissue and in one aspect to cut,dissect and separate tissue/vessels. In particular embodiments, thesystems and processes include the application of RF energy tomechanically compressed tissue to thereby fuse, weld, coagulate, seal orcut the tissue. In various embodiments, the determination of theend-point of the electrosurgical process is given by monitoring oridentifying the phase shift of voltage and current during the process.In one embodiment, unlike impedance, the phase shift changes are morepronounced at times where the tissue desiccates and the fusion processcompletes, and hence offers a more sensitive control value than theimpedance. Accordingly, the application of RF energy via anelectrosurgical unit in conjunction with the measuring or monitoring ofphase shift via an electrosurgical controller are provided to fuse,weld, coagulate, seal, cut or otherwise electrically modify or affectvessels and tissue in accordance with various embodiments ofelectrosurgical system.

In one embodiment, measurement of the dielectric properties of thetissue and control and feedback of the phase difference allows for aprecise control and feedback mechanism for various tissue types,regardless of the tissue size. For example, a controller of theelectrosurgical unit is configured to determine the product ofdielectric constant and conductivity, as well as the phase differencebetween the applied voltage and current to monitor and control thetissue electrosurgical process. In particular, control and feedbackcircuitry of the controller determines when the phase difference reachesa phase shift value determined by the results of dielectric and/orconductivity measurements. When such a threshold or derived threshold isreached, the electrosurgical process is terminated or another operationis commenced or condition activated. An indicator, e.g., visual oraudible, is provided to signal the termination or state/operation changeand in one aspect the controller restricts (completely, nearlycompletely or to a predetermined minimum) further delivery of electricalenergy through the electrodes. In one embodiment, the electrosurgicalinstrument in conjunction with the controller thereby providesatraumatic contact to the connecting tissue and provides enough burstpressure, tensile strength, or breaking strength within the tissue.

In one embodiment, instead of the tissue quickly reaching apre-determined phase (e.g., ranging from 40 to 60 degrees, depending ontype of tissue), the measured phase shift approaches the cut-offthreshold asymptotically. Such an asymptotic approach can require anextended amount of time to reach a final phase threshold. As such,instead of depending on the phase value to reach a definite value alone,additionally the derivate of the phase can be used to avoid asymptoticapproaches to a finalized phase value. Additionally, the determinedphase value can be overshot without being detected or before theprocessor is able to recognize that a final phase stop has been reached.As such, instead of solely relying on the phase value to reach adefinite value alone, the derivate of the phase is also used.

As previously described and described throughout the application, theelectrosurgical unit ultimately supplies RF energy to a connectedelectrosurgical instrument. The electrosurgical unit ensures that thesupplied RF energy does not exceed specified parameters and detectsfaults or error conditions. In various embodiments, however, anelectrosurgical instrument provides the commands or logic used toappropriately apply RF energy for a surgical procedure. Anelectrosurgical instrument includes memory having commands andparameters that dictate the operation of the instrument in conjunctionwith the electrosurgical unit. For example, in a simple case, theelectrosurgical unit can supply the RF energy but the connectedinstrument decides how much energy is applied. The electrosurgical unithowever does not allow the supply of RF energy to exceed a set thresholdeven if directed to by the connected instrument thereby providing acheck or assurance against a faulty instrument or tool command.

In accordance with various embodiments, continuous and/or periodicallymonitoring the phase value of the tissue being contacted can becorrelated to a transition from one tissue condition or type to the nextor from one tissue condition or type to no contact. In one illustratedembodiment, an obturator 41 includes two electrodes 44 a, 44 b used tomonitor the phase of the tissue being contacted (FIGS. 37A-B). As theobturator is inserted into the abdominal cavity, the phase value can beused to indicate the point at which the tip of the obturator is insideor through the abdominal wall at which point the surgeon can begininsufflation. This entry point can be indicated with a visual, audibleor tactile alert. It should be appreciated that an insufflation needle,a probe or similar instruments can likewise be configured as theobturator to ensure that a specific entry point or condition isidentified as appropriate for a specific surgical procedure. Similarapplications can also be applied to the placement of stents, ensuringproper contacts of grounding pads and the like. Additionally, utilizingphase value, tissue identification or condition can assist in replacingor removing the need for tactile feedback. For example, in roboticsurgical operations and instruments used therein phase/tissueidentification monitoring can remove the need to “feel” that tissue isbeing cut, sealed or grasped or to exert a particular pressure toperform such operations.

In various embodiments, continuous and/or periodically monitoring of thephase value of the tissue being treated can be correlated to either achange in tissue type or a change in the tissue properties due todelivery of energy. In one embodiment, based on the monitoring of thephase value of tissue, the output current and voltage to the instrumentcan be modified (e.g., increased or decreased based on the desiredtissue effect (Cut, Coag, or Fuse)), electrodes can be activated ordeactivated, and delivery of energy to the active accessory can begin orend.

Electrosurgical modality transitions based on the phase value of thetissue for electrosurgical instruments in accordance with variousembodiments of the invention can be characterized as:

-   -   1. Coagulate to Cut    -   2. Coagulate to Cut to Coagulate (Automatic shut-off—RF energy        shut off when a phase value is reached or exceeded)    -   3. Coagulate to Cut to Coagulate (User shut-off—RF energy shut        off when the surgeon releases the delivery of energy)    -   4. Cut to Coagulate (Automatic shut-off)    -   5. Cut to Coagulate (User shut-off)

In one embodiment, when coming into contact with tissue of specificphase values, the modalities (Cut, Coag, and Fuse) of the activeinstrument could be rendered active or inactive. In another embodiment,when coming into contact with tissue of specific phase values, aninstrument can automatically provide energy to the tissue (cut,coagulate, fuse, weld or any combination thereof and/or the above notedmodalities) until a predetermined phase value is reached.

In one embodiment, a visual, audible, and/or tactile indication can beused to indicate a tissue type that the active instrument is in contactwith and thereby the electrosurgical instrument can probe for a specifictissue type. When used in combination with multiple electrodes of theactive electrosurgical instrument, combinations of tissue type could beindicated visually, audibly, and/or tactilely and specific electrodescan be activated to provide energy to a portion of the device as desiredto perform a specific surgical operation and based on the specifictissue.

In one embodiment, in order to cut tissue using bipolar RF energy, thetissue being treated cannot be desiccated or dehydrated to a point inwhich the collagen seal is all that remains. At this point the “seal” isunable to conduct electricity in the manner necessary or safely cut thetissue utilizing bipolar energy delivery (e.g., tissue resistance is toohigh). Likewise, at this point, cutting the seal or the tissue aroundthe seal utilizing a mechanical (non-energized) blade or cuttinginstrument can also be difficult due to for example the tissuecalcifying. Therefore, when utilizing phase values to identify thetransitions of “pre-cut” or “partial seal”, the tissue can be coagulatedto known phase value less than the predetermined phase value indicatedfor complete tissue coagulation. Subsequently, cutting is performed(either mechanically or electrically). After cutting, energy deliverycan be continued until a predetermined phase values indicated forcomplete tissue sealing is reached.

It should be appreciated that the tissue to be cut should have minimalthermal damage or desiccation to ensure that the tissue is stillconductive to be electrically cut. In one embodiment, theelectrosurgical instrument provides that about 1-2 mm of lateral thermaldamage outside of the jaws of the device at a phase shift of 45°. Thespacing between the coagulating electrodes electrosurgical instrument isabout 0.040″ or lmm such that at a phase shift beyond 45° the tissue isdesiccated too much to be cut effectively. As such, in one embodiment,the larger the spacing between electrodes, the higher a pre-cuttransition point or condition can be set and a lower pre-cut transitionsupports closer electrode spacing. The lower pre-cut transitionrepresents the phase value in which less coagulation occurs versuscomplete tissue coagulation. Additionally, applying RF energy, e.g.,voltage faster or at a high or steep rate, is provided to support closerelectrodes as the pre-cut transition is lower than a pre-cut transitionwith larger spacing between electrodes. Likewise, applying RF energy ata slower or less steep rate can be provided for larger spacedelectrodes. Additionally, with the tissue being enclosed in betweenjaws, tissue within the confines of the jaw subjected to highertemperatures than on the outside edges of the jaw. As such, tissue lessconfined or subject to lower temperatures can have reduced thermaldamage and thereby a higher pre-cut transition point can be used.

Referring to FIGS. 40-42, in one embodiment, a pre-cut process is shownwhich initially starts for example by the receipt of a cut command (601)from the activation of a button or switch on the actuator. Theactivation of the cut button is communicated or recognized by theelectrosurgical unit coupled to the electrosurgical instrument. In oneembodiment, a processor within the electrosurgical unit instructs orinitiates the output or supply of RF energy (603) to the electrosurgicalinstrument. However, the RF energy supplied is not energy sufficient tocut tissue disposed at the jaws of the electrosurgical instrument.Instead the RF energy supplied is used for coagulation which is lowerthan the energy sufficient to cut tissue. The processor monitors thephase between the current and voltage of the RF energy being supplied tothe tissue (605). In one embodiment, through current and voltagemonitoring circuitry and filters, the phase between the current andvoltage of the RF energy is monitored. A comparison is made to a pre-cutphase condition or switch (607). In one embodiment, the pre-cut phasecondition is a predetermined value or range of values that is specificfor the particular electrosurgical instrument and the type of tissueindicated to be used or specifically used or to be treated by theinstrument. In other embodiments, the pre-cut phase condition isdetermined dynamically based or relative to initial or periodicdeterminations about the tissue type via for example tissue permittivityand/or conductivity measurements to identify different predeterminedvalues or range of values for a given tissue type. For example, aninitial determination of a tissue type is used to lookup or compare to atable of values, e.g., pre-cut phase values, that are experimentally orotherwise predetermined to be the optimal or specific phase value toidentify a pre-cut phase condition.

As previously described, the pre-cut phase condition is identified as apoint or condition in which the tissue being applied with RF energy isnearly coagulation but less than or not up to the point of completecoagulation, e.g., near complete desiccated, dehydrated and/orcalcification of the tissue. If it is not determined that the pre-cutphase switch is reached or exceeded, the process continues as the RFenergy continues to be supplied and the phase monitored. Once it isdetermined that the pre-cut phase condition has been met, cutting of thetissue then proceeds. In one embodiment, the processor commands orinitiates the raising or initiation of the RF energy suitable forcutting tissue at the jaws of the electrosurgical instrument (609). Inone embodiment, the application of RF energy to pre-cut and then cuttissue is quick such that the rate at which the electrosurgical unitreaches or provides the maximum output voltage is accelerated. If thereis a long ramp-up cycle or step function for the voltage to follow, thetissue intended to be cut will be only coagulated. As such, by the timethe electrosurgical unit reaches the cut voltage levels the tissue willbe too dessicated to properly cut.

In one embodiment, the process continues as phase between appliedcurrent and voltage is measured and/or monitored to determine or ensurethat the tissue is properly cut. Additionally, in one embodiment, afterthe tissue is cut, complete coagulation of the tissue can be performedor initiated as RF energy for coagulation is supplied again to thetissue and a determination is made that the tissue has been coagulated.

The tissue pre-cut and then cut is the same or nearly the same, but itshould be noted that the tissue can refer to surrounding tissue firstbeing coagulated to a pre-cut condition and tissue between the nearlycoagulated tissue is then cut. The application of the coagulation RFenergy and/or cut RF energy is also dependent on the electrodessupplying the associated RF energy. As such, the tissue affected canalso be based on the location or application of the RF energy from theelectrode locations to be pre-cut and then a cut using different sets ofelectrodes. For example, when a cut command is initiated, one or moreelectrodes can be energized to apply RF energy to coagulate tissue incontact with the one or more electrodes and once a pre-cut condition isreached, one or more different electrodes are energized to apply RFenergy to cut tissue in contact with these different electrodes. Thus,in one embodiment, when a cut button is activated on the electrosurgicalinstrument, tissue in one area may be supplied RF energy for coagulationto a pre-cut condition and a different tissue in a different are may besubsequently supplied RF energy to cut the different tissue. In oneembodiment, one or more electrodes are used in transmitting RF energyfor coagulation and one or more electrodes different from the otherelectrode used for coagulation are used in transmitting RF energy forcutting. Additionally, one or more electrodes can be used as a common orshared electrode utilized to accommodate both the transmission of RFenergy for coagulation and cutting.

In one embodiment, an electrosurgical unit 420 can comprise input/outputcircuitry 422, RF supply circuitry 424, a phase discriminator 426 and aprocessor 428. One or more circuitry may be incorporated into anassociated circuitry. For example, the RF supply circuitry may beincluded with the input/output circuitry and vice versa. Theinput/output circuitry receives and transmits RF energy from the RFsupply circuitry and out of the electrosurgical unit and to a connectedelectrosurgical instrument (not shown). The input/output circuitry alsoreceives tool data and/or tissue data from the electrosurgicalinstrument and/or through a connector therebetween. In one embodiment,the phase discriminator calculates a phase difference between theapplied voltage and current from the RF supply circuitry. In oneembodiment, the applied voltage and current are rectified and comparedor combined, e.g., through an XOR logic gate, to generate a pulse widthmodulated signal. The duty cycle of the generated signal mirrors orrepresents the phase difference between the applied voltage and current.The determined phase difference is then supplied to a processor thatcompares to a predetermined phase threshold based on a particular tissuein contact with the electrosurgical instrument. In one embodiment, theprocessor provides the above described process of determining a pre-cutcondition to completing a cut.

In one embodiment, an electrosurgical generator includes an RF amplifier633, RF amplifier control and monitor 634, energy monitor 642 and relayand tissue measurement 635. The electrosurgical generator is coupled toa 120 Hz Voltage main input. The main input is isolated with a lowleakage isolation transformer of a power supply 631. The power supplyprovides operational voltages for the control processor 637 and the RFamplifier 633. Additionally, the power supply includes two 50VDC outputmodules connected in series to provide a total output of 100VDC and 8Amps. RF power is generated by the RF amplifier, e.g., a switched modelow impedance RF generator that produces the RF output voltage. In oneembodiment, a 500 peak cut voltage for cutting and 7 Amp current forcoagulation/fusing is generated.

Fusing tissue in one embodiment involves applying RF current to arelatively large piece of tissue. Because of the potentially large toolcontact area tissue impedance is very low. Accordingly, to deliver aneffective amount of RF power, the current capability of the RF amplifieris large. As such, where a typical generator might be capable of 2 to 3amps of current, the RF amplifier of the generator can supply more than5 Amps RMS into low impedance loads. This results in rapid tissue fusionwith minimal damage to adjacent tissue.

The RF amplifier circuitry has redundant voltage and current monitoring.One set of voltage and current sensors are connected to the RF amplifiercontrol and monitor and are used for servo control. The voltage andcurrent can also be read by the processor 637 using an analog to digitalconverter (ADC) located on the RF amplifier control and monitor. The RFamplifier control and monitor also has an analog multiplier, whichcalculates power by computing the product of the voltage and current.The RF amplifier control and monitor uses the average value of voltageand current and does not include a phase angle and thus is actuallycalculating Volt Amps Reactive (VAR) rather than actual power. A secondset of voltage and current sensors are also connected to the energymonitor 642. The signals are connected to an ADC for redundantmonitoring of the voltage and current. The processor multiplies thevoltage and current readings to verity that power output does not exceed400 Watts. The energy monitor has monitoring circuits that arecompletely independent of the RF amplifier control and monitor. Thisincludes the ADC, which has an independent voltage reference.

The RF amplifier in one embodiment is a switching class D push pullcircuitry. As such, the amplifier can generate large RF voltages into ahigh tissue impedance, as well as large RF currents into low tissueimpedance. The output level of the RF amplifier is controlled by PulseWidth Modulation (PWM). This high voltage PWM output signal is turnedinto a sine wave by a low pass filter on the RF amplifier. The output ofthe filter is the coagulation output of the RF amplifier. The output isalso stepped up in voltage by an output transformer resulting in the cutoutput of the RF amplifier. Only one output is connected to the controlservo on the RF amplifier control and monitor at a time and only oneoutput is selected for use at a time.

Coupled to the RF amplifier is the RF amplifier control and monitor 634.The RF amplifier control and monitor 634 in one embodiment receivesvoltage and current set points, which are input by the user through auser interface, to set the output level of the RF amplifier. The usersets points are translated into the operating levels by digital toanalog converters of the RF amplifier control and monitor. The user setspoints are translated into the operating levels by digital to analogconverters of the RF amplifier control and monitor. The set points inone embodiment include a maximum voltage output, maximum current output,maximum power output, and a phase stop. The servo circuit of the RFamplifier control and monitor controls the RF output based on the threeset points. The servo circuit as such controls the output voltage of theRF amplifier so that the voltage, current, and power set points are notexceeded. For example, the output of the ESG is restricted to be lessthan 400 watts. The individual voltage and current set point can be setto exceed 400 watts depending on the tissue impedance. The power servohowever limits the power output to less than 400 watts.

The RF output voltage and current are regulated by a feedback controlsystem. The output voltage and current are compared to set point valuesand the output voltage is adjusted to maintain the commanded output. TheRF output is limited to 400 Watts. Two tool connections are supported byusing relays 635 to multiplex the RF output and control signals. The EMIline filter 636 limits the RF leakage current by the use of an RFisolation transformer and coupling capacitors.

The cut and coagulation output voltages of the RF amplifier areconnected to the relay and tissue measurement circuitry 635. The relayand tissue measurement circuitry in one embodiment contains a relaymatrix, which steers the RF amplifiers output to one of the three outputports of the electrosurgical unit. The relay matrix also selects theconfiguration of the tool electrodes. The RF output is always switchedoff before relays are switched to prevent damage to the relay contacts.To mitigate against stuck relays steering RF to an idle output port eachoutput port has a leakage current sensor. The sensor looks forunbalanced RF currents, such as a current leaving one tool port andreturning through another tool port. The current sensors on are locatedon the Relay PCB, and the detectors and ADC are on the energy monitorPCB. The CPU monitors the ADC for leakage currents. Any fault detectedresults in an alarm condition that turns off RF power.

The relay and tissue measurement circuitry also contains a low voltagenetwork analyzer circuit used to measure tool impedance before RF poweris turned on. The circuit measures impedance and tissue phase angle andin one embodiment using a 10V signal operating at 100 Hz. The processor637 uses the impedance measurement to see if the tool isshort-circuited. If a Tool A or B output is shorted the system warns theuser and will not turn on RF power. The RF amplifier is fully protectedagainst short circuits. Depending on the servo settings the system canoperate normally into a short circuit, and not cause a fault condition.In one embodiment, initial impedance and/or phase measurements candetermine if the jaws are open and/or having no tissue in contact withthe jaws and/or the jaws are dirty, e.g., excessive or interferingeschar build-up.

Voltage and current feedback is provided using isolation transformers toinsure low leakage current. The processor 637 computes the power outputof the RF amplifier and compares it to the power set point, which in oneembodiment is input by the user. The processor also monitors the phaselag or difference between current and voltage. Additionally, in oneembodiment, the processor matches the different phase settings, whichdepend on tissue types to the monitored phase difference. The processoras such measures a phase shift of tissue prior to any application of RFenergy. As will be described in greater detail below, the phasemeasurement is proportional to tissue permeability and conductivity thatuniquely identifies the tissue type. Once the tissue type is identified,the phase angle associated with an end point determination of thattissue type can be determined. The generator in one embodiment has threeRF output ports (Tool A, Tool B and generic bipolar). The tool A and Bports 639 are used to connect smart tools, while the generic bipolarport 640 supports standard electro surgical tools. Audible tones areproduced when the RF output is active or an alarm condition exists.

The hand and foot controls are also isolated to limit leakage current.The control processor checks the inputs for valid selections beforeenabling the RF output. When two control inputs from the switches aresimultaneously activated the RF output is turned off and an alarm isgenerated. Digital to analog converters are used to translate controloutputs into signals useable by the Analog Servo Control. The controlset points are output voltage and current. The analog to digitalconverter is used to process the analog phase angle measurement. VoltageRMS, current RMS, and power RMS information from the controller is alsoconverted into a form usable for presentation to the user. The digitalI/O bus interface 638 provides digital communication between the user,controller and hand/foot switches. Isolation circuitry is used toeliminate a possible leakage path from the electrosurgical generator. Italso provides communication between the user and the generator though adata channel protocol.

In one embodiment, there are four tool Interface circuits in the unit.These circuits are used to electrically isolate the user input switchesfrom mains power inside the system. The four tool interface circuits areidentical and have an on board microprocessor to read the user switchinputs as well as the tool crypto memory and script memories. The switchclosure resistance is measured with an ADC to eliminate a contaminatedswitch contact being read as a closure. Switch closures below 300 Ohmsare valid, while any reading above 1000 Ohms is open. Readings between300 and 1000 Ohms are considered to be faulty inputs.

The four tool interface circuits communicate with the processor using anRS485 network. Each tool interface circuit has jumpers to select itsaddress and location in the unit. The RS485 interface is isolated toeliminate any potential leakage current paths. One tool interfacecircuit is connected to each of the Tool A and B ports. A third toolinterface circuit is connected to the DC output port, and the fourthcircuit is connected to the rear panel foot switch inputs. The processoris the network master and each of the four circuits is a network slave.The processor polls each circuit for input. The tool interface circuitrycan only reply to commands. This makes the network deterministic andprevents any kind of dead lock. Each Tool Interface circuit is connectedto a System OK logic signal. If a system error is detected by a ToolInterface circuit, this signal is asserted. The processor monitors thissignal and indicates a fault. This signal also has a hardware connectionto the RF amplifier control and monitor and will disable the RFamplifier when asserted. A system error could be two input switchesactivated at the same time, or a loss of communication with theprocessor. The Tool A & B ports as well as the DC port have a microswitch that detects when a tool is plugged into the receptacle. Untilthis switch is depressed the Tool Interface circuit front panelconnections are configured off to prevent any leakage current flowingfrom front panel connections. Once the switch is depressed the ToolInterface allows the processor to initiate reads and writes to the toolcrypto memory and script memory. Once a tool is detected a window opensin the user interface display showing the type of tool connected andstatus. The generic bipolar port supports legacy tools, which do nothave any configuration memory. The tissue measurement circuitry is usedto monitor the bipolar connection contacts. When a bipolar tool isconnected the tool capacitance is detected and the processor opens thebipolar tool window on the user interface display and shows status forthe bipolar tool. The DC port is used to interface with 12 Volt DCpowered custom surgical tools. When a tool is plugged into this port awindow opens in the user interface display showing the type of toolconnected and status. When the DC tool script commands power on, theprocessor closes a relay on the Power Control and Isolation circuitry643 turning on the isolated 12 Volt tool power.

The power control and isolation circuitry 643 has two other features. Itcontrols the 100 Volt power supply that drives the RF amplifier. Thispower supply is turned on by a relay controlled from the RF amplifiercontrol and monitor. The processor commands this power supply on via theRF amplifier control and monitor. If the RF amplifier control andmonitor is reset or detects a fault condition, the relay will notoperate leaving the 100 Volt power supply off. Also located on the powercontrol and isolation circuitry is a RS485 isolation circuit that addsan extra layer of isolation.

The front panel interface circuitry 641 is used to connect the frontpanel control switches and LCD display to the processor. The front panelinterface circuitry also contains a microprocessor, which is powered byan isolated standby power supply, which is on whenever the main powerswitch is on. When the front panel power switch is pressed, themicroprocessor uses a relay on the Power Control and Isolation circuitryto turn on the main logic power supply. When the button is pressed toturn power off, the microprocessor signals a power off request to theprocessor. When the processor is ready for power to be turned off itsignals the microprocessor to turn off power. The power control relay isthen opened, turning off the main power supply.

In one embodiment, the generator accepts only single switch inputcommands. With no RF active, e.g., RF energy applied, multiple switchclosures, either from a footswitch, tool, or a combination of footswitchand tool are ignored. With RF active, dual closures shall cause an alarmand RF shall be terminated. The footswitch in one embodiment includesmomentary switches providing activation of the application of RF energy.The switches for example when manipulated initiates activation of the RFenergy for coagulation, for cutting and/or sequenced coagulation orcutting. A two-position pushbutton on the foot pedal switch allowstoggling between different tools. The active port is indicated on thedisplay of the generator and an LED on the hand tool.

In one embodiment, all RF activation results in a RF ON Tone. Activationtone volume is adjustable, between 40 dBA (minimum) and 65 dB (maximum)with a rear panel mounted control knob. The volume control however doesnot affect audio volume for alarms. Also, in one embodiment, a universalinput power supply is coupled to the generator and operates over theinput voltage and frequency range without the use of switches orsettings. A programming port in one embodiment is used to download codeto the generator and is used to upload operational data.

The generator in one embodiment provides output power has a 12V DC at 3Amps. Examples of such tools that use DC power are, but are not limitedto, a suction/irrigation pump, stapler, and a morcellator (tool fordividing into small pieces and removing, such as a tumor, etc.). The DCconnector has intuitive one-way connection. Similar to the other toolreceptacles, a non-sterile electronic chip module is imparted into theconnector of the appropriate DC-powered hand tool by a one-time, one-waylocking mechanism. Tool-specific engravings on both the connector andchip module ensure that the chip module fits only to the type of toolfor which it has been programmed. The chip connector allows toolrecognition and the storage of data on tool utilization. The DCconnector is also configured to prevent improper insertion. Thegenerator is also configured to recognize the attached DC-powered tool.The generator reads configuration data from the tool connector, allowingtool recognition and the storage of tool utilization data.

In one embodiment, phase measurement is a relative measurement betweentwo sinusoidal signals. One signal is used as a reference, and the phaseshift is measured relative to that reference. Since the signals are timevarying, the measurement cannot be done instantaneously. The signalsmust be monitored long enough so that difference between them can bedetermined. Typically the time difference between two know points (sinewave cross through zero) are measured to determine the phase angle. Inthe case of the phase controller, the device makes the output sine wavewith a precise crystal controlled clock. That exact same clock is use toread the input samples with the analog to digital converter. In this waythe output of the phased controller is exactly in phase with the inputof the phase controller. The phase controller in one embodiment comparesthe input sine wave signal to a reference sine wave to determine theamount of phase shift.

The phase controller does this comparison using a mathematical processknown as a Discreet Fourier Transform (DFT). In this particular case1024 samples of the input signal are correlated point by point with botha sine function, and a cosine function. By convention the cosine part iscalled real, and the sine part is called imaginary. If the input signalhas no phase shift the result of the DFT is 100% real. If the inputsignal has a 90-degree phase shift the result of the DFT is 100%imaginary. If the result of the DFT has both a real and imaginarycomponent, the phase angle can be calculated as the arctangent of ratioof the imaginary and real values.

It should be appreciated that the phase angle calculation is independentof units of the real and imaginary numbers. Only the ratio matters. Thephase results of the phase controller are also independent of gain andno calculation of impedance is made in the process of calculating thephase angle. By performing a DFT, the phase controller encodes the phasemeasurement as a pair of numbers.

In accordance with various embodiments, precise knowledge of the phaseendpoint prior to energy delivery allows for tighter control, and fordelivery of more current than other electrosurgical units (7 A, 400 W).In accordance with various embodiments, the memory capability of theinstrument key portion of each instrument connector allows the readingand writing of information between the electrosurgical unit and theinstrument key or connector. The information can include recordingtreatment data (energy profile, tissue types, etc.) or data to preventdevice reuse. In one embodiment, the use-before-date (UBD), number ofuses, device serial number and expiration after first use values areencrypted to prevent reprocessing and reuse of the instrument key. Inone example, to assist in managing inventory, the information mayinclude the serial number of the electrosurgical unit that can beretrieved and stored into the memory upon connection of the instrumentto the unit. The serial number or similar information is then used inparallel with lot and sales data to locate the electrosurgical unitand/or track electrosurgical unit's movements. Likewise, locators ortrackers using GPS, RFID, IP addresses, Cellular Triangulation can beincorporated in the instruments and/or electro surgical unit to locateand track electrosurgical units or instruments.

In one embodiment, the information may include metrics such as recordingtissue types encountered during a procedure and/or tracking performanceof an instrument or electrosurgical unit (how often used, number ofprocedures, and so on). Pre-customized surgeon settings can also beincluded in which the device output parameters (e.g., voltage, current,and power) stored in the connector or instrument key and read into theelectrosurgical unit when connected. The specific settings can beprogrammed or stored prior to shipment of the instrument/connector.Diagnostic information on instrument/electrosurgical unit can also beincluded. For example, calibration and output verification informationcan be stored on the electrosurgical unit and then downloaded to theinstrument key when connected. In one embodiment, software upgrades canalso be delivered via the memory and the instrument ports on theelectrosurgical unit.

In one embodiment, the electrosurgical generator or unit canautomatically sense or identify a standard bipolar instrumentinsertion/connection. In one embodiment, the electrosurgical unit cancompensate for or enhance a standard bipolar instrument to phase monitorand/or identify tissue or its condition. For example, a tissuemeasurement circuitry could be included in the electrosurgical unit oras an intermediate connector between the instrument and electrosurgicalunit. The circuitry and/or program could include phase monitoring and/ortissue type or condition identification functionality. The tissuemeasurement circuitry in one embodiment can include a phase measurementadjustment circuit or program to account for impedance in the circuitryand cables that run between the tissue and the tool port. The circuitrymay also include temperature correction as an actual change in phasevalue due to the instrument may be less than potential changes due totemperature fluctuations.

Using the phase difference between voltage and current as a controlvalue in a fusion or welding process, instead of the impedance, can befurther shown when characterizing the tissue electrically. Whenconsidering vessels and tissue to be a time-dependant ohmic resistor Rand capacitor C in parallel (both of which depend on the tissue size andtype) the phase difference can be obtained with

${R = \frac{\rho \cdot d}{A}},$

where R is the ohmic resistance, ρ the specific resistance, A the area,and d the thickness of the fused tissue,

${X_{C} = \frac{1}{\omega \cdot C}},$

where X_(c) is the capacitive impedance, ω the frequency, and C thecapacity of the tissue, and

${C = \frac{ɛ \cdot ɛ_{0} \cdot A}{d}},$

where ε e and ε₀ are the relative and absolute permittivity.

The phase difference φ can then be expressed as

${\varphi = {{\arctan\left( \frac{X_{C}}{R} \right)} = {\arctan\left\lbrack \left( {\omega \cdot ɛ \cdot ɛ_{0} \cdot \rho} \right)^{- 1} \right\rbrack}}},$

where ρ is equal to (1/conductivity).

As such, the difference between monitoring the phase difference φ asopposed to the (ohmic) resistance R is that φ depends on the appliedfrequency Ω and material properties only (namely, the dielectricconstant ε and the conductivity), but not on tissue dimensions (namelythe compressed tissue area A and tissue thickness d). Furthermore, therelative change in phase difference is much larger at the end of thefusion process than the change in tissue resistance, allowing for easierand more precise measurement.

In addition, with measurement of the initial dielectric properties ofthe tissue (dielectric constant ε and conductivity) at a certainfrequency, the type of tissue can be determined. The dielectricproperties for various types of biological tissue, arranged byincreasing values of the product of dielectric constant c andconductivity) are given in FIG. 30 at a frequency of 350 kHz (which isin the frequency range of a typical electrosurgical generator). Bymeasurement of the product of dielectric constant c and conductivity ofthe tissue (which are material characteristics and independent of tissuedimensions) before the actual tissue fusion or welding process, thephase shift required to adequately fuse or seal the specific biologicaltissue can be determined. The phase shift required to reliably fuse orseal the respective type of tissue is measured as function of theproduct of dielectric constant c and conductivity of the tissue.Additionally, endpoint determination can be represented as a function ofan initial phase reading of the tissue determination and likewise endpoint determination can be represented as a function of tissueproperties (conductivity times relative permittivity).

As a result, (a) measurement of the dielectric properties of the tissueand (b) control and feedback of the phase difference allows for aprecise control and feedback mechanism for various tissue types,regardless of the tissue size and allows employing standardelectrosurgical power supplies (which individually run in a very closerange of frequencies). It should be noted that however that specificfrequency of the tissue properties measurement is performed can be thesame or different from the specific frequency of the phase. If thetissue measurement is based on the driving frequency of the generator,and various generators are used (all of which run in a close range offrequencies) though, the end points will be different. Hence, for such acase, it can be desirable to (1) use an external measurement signal(which is at the same frequency), or (b) utilize a stand-alonegenerator.

As such, the controller is configured to determine the product ofdielectric constant and conductivity, as well as the phase differencebetween the applied voltage and current to monitor and control thetissue fusion or welding process. In particular, control and feedbackcircuitry of the controller determines when the phase difference reachesthe phase shift value determined by the result of the dielectric andconductivity measurements. When this threshold is reached, the fusion orwelding process is terminated. An indicator, e.g., visual or audible, isprovided to signal the termination and in one aspect the controllerrestricts (completely, nearly completely or to a predetermined minimum)further delivery of electrical energy through the electrodes. As such,the tool generating the seal, weld or connection of the tissue providesatraumatic contact to the connecting tissue and provides enough burstpressure, tensile strength, or breaking strength within the tissue.

In one embodiment, a bipolar/monopolar single connector plug is providedto allow the connection of monopolar instruments to the electrosurgicalunit. In one embodiment, the connector includes a grounding pad port 310that acts as another electrode (e.g., a 6^(th) electrode (F)) that theelectrosurgical unit 420 turns on and off through internal relays in theelectrosurgical unit (FIGS. 38-39). Based on the programming of therelay/electrode configuration or pattern on the instruments (e.g.,stored in memory of the connector), an electrosurgical instrument 450can cut and coagulate in either a bipolar manner, monopolar manner ofboth. In one embodiment, in bipolar mode, the electrosurgical unit 420utilizes two or more electrodes, e.g., electrodes designated “B” and“C”, to create active and return paths and in monopolar mode, theelectrosurgical unit utilizes one or more of the electrodes as active,e.g., electrodes designated “A” through “E”, and only an electrode wherethe grounding pad 315 would be designated or used as the return onlyelectrode 310, e.g., electrode designated “F”. In one embodiment,switches internally or externally on the electrosurgical instrument, theconnector and/or the port can be used to identify or notify theelectrosurgical unit that a monopolar operation is being used.Additionally, in one embodiment phase measurements of applied RF energycan be used to identify if the monopolar pad is removed, not providingsufficient contact with the patient and/or electrical conductivity tothe electrosurgical instrument.

Further examples of the electrosurgical unit, instruments andconnections there between and operations and/or functionalities thereofare described in U.S. patent application Ser. Nos. 12/416,668, filedApr. 1, 2009, entitled “Electrosurgical System”; 12/416,751, filed Apr.1, 2009, entitled “Electrosurgical System”; 12/416,695, filed Apr. 1,2009, entitled “Electrosurgical System”; 12/416,765, filed Apr. 1, 2009,entitled “Electrosurgical System”; and 12/416,128, filed Mar. 31, 2009,entitled “Electrosurgical System”; the entire disclosures of which arehereby incorporated by reference as if set in full herein.

Although this application discloses certain preferred embodiments andexamples, it will be understood by those skilled in the art that thepresent inventions extend beyond the specifically disclosed embodimentsto other alternative embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Further, the variousfeatures of these inventions can be used alone, or in combination withother features of these inventions other than as expressly describedabove. Thus, it is intended that the scope of the present inventionsherein disclosed should not be limited by the particular disclosedembodiments described above, but should be determined only by a fairreading of the following claims.

1. An electrosurgical system comprising an electrosurgical instrumentcomprising: an elongate shaft having a proximal end, a distal end and alongitudinal axis extending from the proximal end to the distal end; afirst jaw connected to the elongate shaft, aligned with the longitudinalaxis of the elongate shaft and being stationary relative to the elongateshaft, the first jaw being entirely conductive and having a cut channelextending lengthwise along and through the first jaw, and the first jawcomprising a monolithic seal surface comprising a plurality of sealpaths surrounding the cut channel and spaced by a plurality of cavitiesbetween each of the plurality of seal paths, each of the plurality ofseal paths having identical widths and differing lengths and each of theplurality of cavities having identical widths and differing lengths; asecond jaw pivotably coupled to the elongate shaft and pivotably movablerelative to the first jaw, the second jaw comprising a first electrode,a second electrode and an insulator positioned between the first andsecond electrodes, the second electrode being shaped and sized like thefirst jaw and being on an upper portion of the second jaw and distalfrom the first jaw, and the first electrode being on a lower portion ofthe second jaw proximate to the first jaw and extending along an outerportion of a distal tip end of the second jaw, the first electrode beingparallel with the second electrode; and a cutting blade connected to ablade shaft disposed within the elongate shaft, the cutting bladearranged to fit within the cut channel of the first jaw; and anelectrosurgical generator arranged to supply radiofrequency (RF) energyto the electrosurgical instrument removably coupled to theelectrosurgical generator, the generator being arranged to supply RFenergy between the first electrode and the first jaw to coagulate tissuein contact with the first electrode and the first jaw and being arrangedto supply RF energy between the first electrode, the second electrodeand the first jaw to coagulate tissue in contact with the firstelectrode, the second electrode and the first jaw.
 2. The system ofclaim 1 wherein the first electrode comprises a monolithic seal surfacecomprising a plurality of seal paths surrounding a second cut channeland spaced by a plurality of cavities between each of the plurality ofseal paths, each of the plurality of seal paths having identical widthsand differing lengths and each of the plurality of cavities havingidentical widths and differing lengths.
 3. The system of claim 2 whereinthe generator is arranged to supply RF energy between the first jaw andthe second electrode to coagulate tissue in front of the second jaw andtissue on at least one side of the second jaw.
 4. The system of claim 3wherein the second electrode and the first jaw share a common electricalcontact in that the generator supplies RF energy between the firstelectrode and the first jaw and between the first electrode, the secondelectrode and the first jaw.
 5. The system of claim 4 wherein when thefirst and second jaws are in an intermediate state between an openposition and a closed position, the first electrode and the first jaware electrically connected to assume a first and second polarity in thattissue positioned between and in contact with the first electrode andthe first jaw are fused when a fusing operation is activated and cuttingby the cutting blade is prevented.
 6. The system of claim 5 wherein thecutting blade is blunt, electrically conductive and positionedperpendicular relative to the first jaw and wherein in the generator isarranged to supply RF energy between the cutting blade and the first jawto cut tissue in contact with the cutting blade and the first jaw. 7.The system of claim 6 wherein the instrument further comprises: anactuator connected to the elongate shaft, the actuator further comprisesa blade trigger connected to the blade shaft, a stationary handle and amovable trigger, the movable trigger being movable towards thestationary handle to close the first and second jaws and movable awayfrom the stationary handle to open the first and second jaws and thecutting blade being movable proximally and distally lengthwise throughthe first and second jaws and within the cut channel of the first jawand the second cut channel of the second jaw; and a distal stop arrangedto interact with a first corresponding stop disposed along the elongateshaft and arranged to prevent distal movement of the blade shaft beyonda distal interaction point of the first corresponding stop of theelongate shaft interacting with the distal stop of the blade shaft whenthe blade shaft is moved distally.
 8. The system of claim 7 wherein theinstrument further comprises a proximal stop arranged to interact with asecond corresponding stop disposed along the elongate shaft and arrangedto prevent proximal movement of the blade shaft beyond a proximalinteraction point of the second corresponding stop of the elongate shaftinteracting with the proximal stop of the blade shaft when the bladeshaft is moved proximally.
 9. The system of claim 8 wherein theinstrument further comprises a spring connected to the blade shaft andbiasing the blade shaft proximally and wherein the proximal stop and thesecond corresponding stop are arranged to prevent the spring frompulling the cutting blade proximally beyond the proximal interactionpoint and the spring, the proximal stop and the second correspondingstop arranged to hold the cutting blade stationary at the proximalinteraction point.
 10. The system of claim 9 wherein the elongate shaftcomprises a cover tube and the first and second corresponding stops aredeformed portions on the cover tube, the deformed portions interactingwith the distal and proximal stops of the blade shaft.
 11. The system ofclaim 10 wherein the instrument further comprises: an internal switchdisposed within the stationary handle and not externally accessible, theinternal switch being activated by a flexible arm extending from themovable trigger and contacting with the internal switch when the movabletrigger is moved towards the stationary handle; and at least oneexternal switch disposed on the actuator and an electrical connectionbeing established with the at least one external switch and the internalswitch being both activated; wherein the generator is arranged to supplyRF energy to the first jaw and the cutting blade with the internalswitch being activated.
 12. The system of claim 11 wherein the at leastone external switch further comprises a first external switch toactivate an electrosurgical activity and a second external switch toactivate a different electrosurgical activity, the first external switchdisposed above the second external switch.
 13. The system of claim 12further comprising a second cutting blade positioned generallyperpendicular to the second jaw and movable proximally and distallylengthwise through the second electrode of the first jaw.
 14. The systemof claim 11 wherein the generator, after the at least one externalswitch is deactivated, is arranged to supply RF energy between the firstelectrode and the first jaw instead of the cutting blade and the firstjaw.
 15. The system of claim 14 wherein the generator is arranged todetermine a phase value of the supplied RF energy between the firstelectrode and the first jaw and to determine when the determined phasevalue of the supplied RF energy equals or exceeds a predetermined phasevalue; wherein the generator, after determining the determined phasevalue of the supplied RF energy equals or has exceeded the predeterminedphase value, is arranged to supply RF energy between the first jaw andthe cutting blade instead of the first electrode and the first jaw,wherein the generator is arranged to determine a phase value of thesupplied RF energy between the first jaw and the cutting blade todetermine when the determined phase value of the supplied RF energyequals or exceeds a second predetermined phase value; and wherein thegenerator, after determining the determined phase value of the suppliedRF energy equals or has exceeded the second predetermined phase value,is arranged to supply RF energy between the first electrode and thefirst jaw.
 16. The system of claim 15 wherein the generator is arrangedto not determine when the determined phase value of the supplied RFenergy equals or exceeds a predetermined phase value when the first andsecond jaws are in the intermediate state.
 17. The system of claim 16wherein the instrument further comprises a cable having a proximal endand a distal end, the distal end of the cable being attached to andextending from the stationary handle, a plug having one end connected tothe proximal end of the cable and another end attached to a connector;and wherein the generator further comprises a tool connector receptacle;and wherein the connector of the instrument is removably attached to thetool connector receptacle and comprises memory circuitry configured tobe utilized by the generator.
 18. The system of claim 17 wherein thetool connector receptacle includes a switch recessed within the toolconnector receptacle that is operatively activated by the connectorbeing inserted into the tool connector receptacle.
 19. The system ofclaim 18 wherein the instrument further comprises a third electrodeconnected to the first jaw and extendable from a first position withinthe first jaw to a second position outside the first jaw and past adistal most end of the first jaw when the first and second jaws are inthe closed position; and wherein the generator is arranged to supply RFenergy between the third electrode and the first jaw.
 20. The system ofclaim 18 wherein the instrument further comprises a sensor adjacent tothe movable trigger arranged to detect a position of the movable triggerto identify the intermediate state.